I have the same model laptop. When I tried to install the drivers for an XP series laptop, it told me they were for a different model. I asked Sony for them and they basically told me I'm out of luck and they won't be bothered supporting XP. I was under the impression I was purchasing a PC, not a Windows Vista work station! Sony is helping Microsoft Legally to do what they have been trying to do illegally for years. I assume Microsoft gave them one hell of a discount on their Vista licenses to do this.
Anyway, I didn't actually come here to rant, but I'm so angry about this I couldn't help vent a little. After many days of searching I was able to get most of the XP drivers. The sound plays fine from the speakers with the Sigmatel audio codec I used, but I didn't get the Realtek driver to work. I assume thats for the digital output. I just disabled it as I will probably never use it. The Volume and mute buttons don't work till after the windows updates. The brightness function keys don't work at all. I didn't actually get a chance to test the modem, but the driver I used installed okay. The camera worked after I installed the driver even though I get an error during install. The chipset driver also worked. Hibernation and standby both cause a bsod so I have them disabled. If you have a place I can send them to, the whole zip file with all the drivers is about 100MB. Just the Sigmatel is about 6.